Mortgage Rate Average Falls to 8.73%: The rate this week for 30-year, fixed-rate mortgages was down from 8.84% last week, according to a Federal Home Loan Mortgage Corp. survey. That average was the lowest since Sept. 22, when it also was 8.73%. The average sank to a 25-year low of 6.74% in October, 1993. On one-year, adjustable-rate mortgages, lenders were asking an average initial rate of 6.60%, down from 6.66% last week. Fixed-rate, 15-year mortgages, a popular option in refinancing, averaged 8.34% this week, down from 8.46% a week earlier. The rates do not include add-on fees known as points.